relationships vs. my life

So for some reason I've been thinking a lot about relationships lately, and I'm not quite sure of how I feel about them. What I do know is that I don't want to be in one, and I feel like its a combination of things that could be either good or bad. Part of me is super focused on school, and being a professional dancer. This is a goal I've had since I was 2 years old, and I don't think I boyfriend/significant other or whatever you wanna call it would help me in any way shape or form in achieving that goal.
The other part of me is just scared of boys. It isn't that I have a 5th grade mentality about boys and am afraid talk to them. i feel like its much deeper than that. I have no idea what a good relationship is supposed to be like. For one, I never saw my mother in one. Of course neither my or my brother's father worked out. I was born out of wedlock and my Dad was having an affair with my Mom, and my brother's Dad just REALLY wasn't right for her. I mean, they're both great Dads to both of us, but relationship wise-THEY SUCKED. Not to mention the rest of the failing relationships and let downs I saw my Mom experience. She never had a guy that made her happy, in fact they almost always did the exact opposite.
As for me my first relationship with "you know who" was a disaster. To this day I can't believe we dated. He was a total petifile who shouldn't have been trying to get his hands on a girl my age. He also took me away from things that I shouldn't have lost. He was very selfish, and I wish he had gotten out of my life sooner. So that of course was a bust. I don't really count the month long "relationship" that I had with...ewww is all I have to say, or the summer after graduation with...even more ewwww.
I don't know what to look for in a guy and I feel like they come with too much drama/baggage. While I can't lie, I have loved with him for the past four and a half years, I don't know what that means. I've always loved him (and always will), but I'm afraid to let myself be in love with him. I mean you have to consider rejection and also the fact that if he did give me a chance he could totally let me down. Now, i couldn't imagine that happening because he's such an amazing friend...but I don't know. He's almost perfect. He's everything that I could imagine the perfect guy being. He's easy to talk to, funny, smart, artistic...not to mention extremely good looking-lol.
He makes me not want to give anyone else a chance. Just knowing that he's out there makes me not care about anyone else in that way. Ugh, why does this have to be so hard?